Thursday, February 08, 2007

Humans are wired to constantly search for causes for (and solutions to) every problem. This is probably our most useful adaptation, but it can lead to certain difficulties, especially for doctors.

Take flu shots, for example. It has been shown conclusively that flu shots do not give you the flu. (They couldn’t give you the flu due to the way they’re designed, but people went and did studies on it anyway.) Yet there are many people out there who swear that flu shots give you the flu. Why?

Flu shots are given during cold and flu season. A certain number of people will come down with an upper respiratory infection in any given week. If one of those people happened to get their flu shot that week, it’s easy to see why they would assume that the shot was to blame. Forever after, they will attest that flu shots give you the flu—and will probably convince a few other people of the same. Trying to argue against this is nearly futile. I attempt a preemptive strike with every flu shot I give, telling them that the shot won’t fully protect them for about two weeks, so they could still catch the flu in that time, but I’m not sure how well this works.

Trying to bring on labor is another example. Studies have shown that NOTHING works to bring on labor, with the exception of the drugs used for formal induction in the medical setting. Castor oil? Doesn’t work. Having lots of sex? Doesn’t work. Scrubbing the floor on hands and knees? Doesn’t work. Nipple stimulation? Doesn’t work. Acupuncture? Doesn’t work. Ankle massage? Doesn’t work. Walking/jumping? Doesn’t work. Stripping the membranes? Doesn’t work. Primrose oil? Doesn’t work. Raspberry tea? Doesn’t work. And so on and so forth.

But wait! I can hear a lot of you (probably most of you) thinking. My doctor recommended having sex, and it worked for me! My best friend used castor oil, and it worked for her! My midwife swears that several of her patients have gone into labor after drinking raspberry tea! I know these things work!

But think about it. No matter what, every pregnant woman eventually goes into labor. And whatever thing she did just beforehand will always be credited with doing the trick. Therefore of course all of these things have “worked” for some people. But when they’ve been formally studied—having fifty pregnant women do nothing while another fifty twiddle their nipples, for instance—the rate at which they go into labor is exactly the same.*

Birth defects are yet another example. I was talking with a pregnant friend recently about how nutty everybody gets about pregnant women doing anything—taking medications, drinking coffee, having a little alcohol, lying on their backs. This hysteria seems to be getting worse and worse. Partly this is just part of the whole trend toward fetishizing pregnancy, I believe, but partly it’s because of the way birth defects occur. There are only a few things that are known to cause terrible birth defects—thalidomide, oral isotretinoin, and a couple other uncommon things—but even if you don’t have exposure to one of those, there is a 2-3% risk of major birth defects. And when one of these spontaneous defects happens, of course everyone starts wondering what caused it, and remembering every cold tablet and cup of coffee and hot bath they took during pregnancy. If you do a retrospective study looking at birth defects, the mothers of babies with defects always remember more exposures to everything than the mothers of healthy infants. But if you do a prospective study, following people through their pregnancies and documenting exposures, there’s no difference between those in which defects occur and those in which they don’t.

If something happens often enough—a colicky baby being fussy, for instance—it’s easier to figure out (by trying a lot of things that don’t consistently work) that nothing you do causes it or cures it, and it just needs to be waited out. Relatively rare things that can occur randomly (getting pregnant, birth defects, most cancers) or that inevitably end with time (pregnancy, a chest cold) are the things that really lend themselves to myth-making about causes and solutions.

The belief that every phenomenon can be explained and every problem solved is a wonderful thing much of the time. It’s great when someone with diabetes understands that eating carbohydrates causes their blood sugar to rise or that taking their medicine brings it under control. But it’s frustrating when someone can’t accept that doctors don’t have the solutions to everything. (The doctors who can’t accept that—and there are many—are even more frustrating.)

I wish I had a better way of explaining this to patients. Sometimes when people ask me “Why did I get this disease?” I’ll answer, “Just bad luck,” and they look at me like I’m crazy. I suppose if I were religious, I could answer, “Only God knows the reason,” but 1) I’m not, 2) my patients might not be either, and 3) even if they are, it could be an annoying thing to hear (“I’m sure God has a reason for why you had this miscarriage!”).

How do you deal with things that can’t be explained?

*UPDATE: OK, I should know better than to use an inflammatory example such as this. I say the following in a comment below, but I’ll add it here too: the induction of labor example was meant mostly as an example of a perfect setup for fallacious beliefs to take hold. Yes, there are studies here and there that suggest that a couple of these things might increase the odds a little bit of delivering earlier (though several of those studies were actually done in conjunction with oxytocin, so I’m not sure that you can count them). But having looked at the evidence, I’m standing by my assertion that none of those things is worth having anyone put themselves out in any way to do, because if they work at all, the effect is teeny-tiny. Remember, negative studies mostly don’t get published, so if there are a few weakly positive studies—or positive weak studies—chances are very good that there are at least a few unpublished negative studies.

I’m not saying that everyone should be induced medically by any means; I think too many people get induced as it is, and if we just waited until babies were done gestating we’d have fewer c-sections. I also think childbirth has been overmedicalized in general—I even think that the evidence supports the superiority of (supervised) homebirth in multiparous women. But the things that I see heavily pregnant women doing to try and bring on labor just seem miserable, and the amount of advice they get about it could give anyone a headache. (Which doesn’t help bring on labor either.)

And yes, I’m having a wretched day, and week for that matter.

38 comments:

Liza
said...

Well, I can certainly attest to the fact that nothing works to bring on labor. I tried every single thing I heard rumors about, except castor oil, since my midwife specifically requested that I not try it because of the unpleasant, er, side effects.

And my 9 lb, 7 oz boy came a week late, after 3 weeks of trying anything I was up to try that day.

That said, I hate not knowing the reasons for things, and in general, I'm not good with the answer "It just happens. We don't know why."

I think doctors get hit with the frustration from that harder than others, because so often doctors behave as though they clearly know the answer, and you the patient, clearly does not. The arrognance tends to hold in place the view that the doctor knows all.

Honestly? I just don't think about them. If there's no way of knowing, what's the point of wondering? Doesn't change anything. A therapist I worked with a long time ago once said that "Why?" is the single most meaningless question in the English language. People asking it aren't really asking a question, and people answering don't often really know the answer. At the time, this pissed me off immensely, but I've come to see that she was right.

Thank you for this thought-provoking post. I hadn't really thought too much about the desperate human need to link cause and effect before. But you're right, it's there, and seeing any effect without being able to pinpoint the cause drives me and probably many other people crazy. I think that it's also connected to our desire to control everything we possibly can. If we can find the cause, then maybe we can control the cause and either bring on or limit the effect. Without the causal link, we just feel totally helpless.

So how do I deal with feeling helpless? I think I sometimes handle it by trying to focus on the random good things that happen without discernable causes, since I think it's probably only the bad things that drive us nutty.

AND it may shorten the duration of the first stage of labour according to this study and this study (which also suggests it's effective at bringing on labour once membranes have ruptured).

The Cochrane review found that breast stimulation MAY be effective at bringing on labour, but more study is needed.

This study found breast stimulation highly effective at cervical ripening and the induction of labour. And since it also found that there were no side-effects, it seems a lot safer than using drugs to induce labour.

Stripping of the membranes works for nulliparas with unfavourable cervixes, according to this study. This study concluded it was effective at inducing labour between 40 and 41 weeks.

Not surprisingly, no-one's actually studied whether cleaning the floor can stimulate labour, or ankle massage or walking/jumping for that matter. There's not much evidence either way about castor oil - no big well-designed studies have been done.

Given that there's actually a lot of evidence that acupuncture is effective, and some evidence that nipple stimulation is effective, and evidence that sweeping of the membranes can be effective, why just dismiss them as "Doesn't work"??

In fact your example of 50 women twiddling their nipples going into labour at the same rate as women who do nothing simply isn't true. In the trial I linked to above, 100 women were studied - 50 who twiddled their nipples (as you put it), 50 who didn't. 46% of the nipple-twiddling group went into labour. Only 12% of the non-nipple-twiddling group went into labour. Seems like a significant difference to me (oh yes, and to the statisticians, who'd describe that difference as "highly significant")

I understand that a lot of these things are simply old wives' tales - cleaning the floor most likely doesn't bring on labour. Castor oil isn't a great idea.

But to dismiss everything that doesn't involve drugs to induce labour as "Doesn't work" seems to me to be close-minded, and not exactly evidence-based medicine!

I heard that having your HUSBAND scrub the floor on his hands and knees brings on labor. It's worth trying, anyway.

How do I deal with things that can't be explained? I think this is where being an atheist is helpful. You can just sort of peacefully accept that shit happens, instead of searching wildly for God's grand plan in the mess.

My mother has always sought to assign herself the blame for anything slightly amiss. Why am I shorter than my older sister? Because her "womb was depleted" when she got pregnant with me, obviously! I try not to do the same self-blaming thing when it comes to my own child. Why is he the way he is? Is it because he was a preemie, because my body was bad at being pregnant? Probably he just is that way, without proximal cause.

This issue ties into malpractice. I once saw an ad on a bus, a malpractice lawyer trying to drum up business. The message was basically this: "Bad outcome? It must be someone's fault!" No, sometimes bad things just happen. Did the cancer patient die because the doctor was negligent? Hmm, might've had something to do with the cancer. Birth complications? These things happen, too. Granted, there are cases of medical malfeasance, but to imply that Someone is always to blame? No.

There is some evidence that stripping membranes and having lots of sex decrease people's likelyhood of going post-term. So in a sense, they increase the likelyhood of labor. But then, I'm a total geek.

Rebekka -- and mwak -- the induction of labor example was meant mostly as an example of a perfect setup for fallacious beliefs to take hold. Yes, there are studies here and there that suggest that a couple of these things might increase the odds a tiny bit of delivering earlier (though several of those studies were actually in conjunction with oxytocin, so I'm not sure that you can count them). But having looked at the evidence, I'm standing by my assertion that none of those things is worth having anyone put themselves out in any way to do, because if they work at all (and I really don't think they do), the effect is teeny-tiny. I'm not saying that everyone should be induced medically by any means -- hey, I'm one of the few doctors who agrees that the evidence supports the superiority of (supervised) homebirth in healthy multiparous women! -- but the things that I see heavily pregnant women running around doing to try and bring on labor just seem miserable, and the amount of advice they get about it -- oy vey.

It's interesting to read this post tonight. I just finished watching a PBS special that detailed an explanation about why some people recovered from/never got at all the bubonic plague. Genetic mutation, it turns out, but for centuries one woman's survival was attributed to the fact that in a delirium of thirst, she drank warm bacon fat. (Interestingly enough, the same mutation that protects one from the bubonic plague also protects against HIV. People with two copies of the gene are unable to get HIV.)

All that to say, if a person is convinced that their own remedy will work for whatever ailment they've got and it won't hurt them, then I usually don't argue with them. It's been my experience that people don't really listen anyway.

On the other end of the spectrum, though, my best friend is convinced that vaccines cause autism and that the human immune system is perfectly capable of fighting off anything that comes along. Nothing I say, no amount of research articles emailed her way will convince her. There's not a thing I can do to force her to vaccinate my nephews, so I've finally stopped arguing with her. I imagine you must feel that way alot in your profession.

Sorry if I'm repeating something someone else has said - just wanted to reply to something you said early on in this post.

Surely nipple stimulation *has* been found to increase the chances of going into labour? I remember this quite clearly because I read up on it at the end of my pregnancy and even made a list of the studies. Can't find the Cochrane review right now (in a rush hence the 'not reading other comments' thing), but I'm sure it exists!

Oh, and - acupuncture? I was actually looking this up for someone just the other day, and according to Cochrane there *has* been one small study showing possible benefit. Unless there's a larger study been done since then which I didn't hear about (always possible, of course, but it sounds like something I'd have heard on the grapevine), then surely this is a case of lack of evidence either way, rather than proof that acupuncture doesn't work? I think the points you made are extremely important, but I think it's also important to remember that - as the old saying has it - absence of evidence does not mean evidence of absence.

Your experience isn't proof that nothing works. It's proof that nothing works in 100% of cases. It can't, on its own, be taken as any more than that. Believing that it can isn't any less fallacious than believing that "I ate curry and went into labour the next day!" is evidence of anything.

If we didn't ask "Why," you'd be treating people with leaches and bleeding them. When we ask "Why" in a systematic and rational way, and accept the data and create theories we do a lot.

There will always be people that don't believe in something even though we have a LOT of data to back it up. This is not rational, but can be explained. We all have lots of superstitious behaviors in our repertoire whether we care to admit to them or not. It can actually be adaptive to have them. It can help us cope.... But....

A scientist has to be willing to be objective. This is what makes science work. (Not going to lecture on the scientific method now though.... ) Normal human beings ask "why" without being objective. I think also, you are bringing up spurious correlations... We are very good at correlating things... and then ascribing causation to them... We KNOW that correlation is NOT causation.... See http://www.venganza.org/about/open-letter/

Correlations are only RELATIONSHIPS... There is a relationship between eating curry and going into labor, but whether the former CAUSED the latter is the question...

(Also, if you don't know about venganza.org, you may want to... pretty funny religion ... heh.)

Okay... rambling now. Sorry about that. I get your frustration, but I don't think ceasing to ask "Why" is the solution.

I'm pretty sure, with enough science, we can even answer your patients when they ask... "Why did I get this disease?" ... (Maybe not soon enough for your patients today, but someday a doctor will be able to answer that question a lot better.)

I should also commend you for admitting that doctors don't know everything...

It's actually wrong of people to assume they do. It's also wrong of people to think that a pill can fix them all the time... Eventually we will know more and doctors will be able to help more people more of the time... But life will probably still be fatal.

(I sense that you had a tough day.) (Didn't mean to come across as difficult in my last comment.)

Your post was great. Love your thought process and approach to your profession. Good for you. And, it really doesn't matter about studies. Proof can be shown to people and they still won't believe you and do what they want anyways. Especially in today's world, everyone wants the easy and fast solution. Why let your body do what comes naturally when you can try some crazy idea your neighbor's mother's college roomate who was going to be a doctor told her worked? It's really not worth the effort to argue, let them stimulate their nipples till the cows come home.

ahhhhh the fine line between correlation and causation. People so often assume that because you do X then Y, that X causes Y. Not always true! Simple statistics. Just because they correlate doesn't mean that's the cause!

On a totally unrelated note (more related to the last post) can you believe that breastmilk really does clear up goopy baby eyes??? Who knew...

I think the search for explanations is our way of trying to find some control over our universe. I know when I had a miscarriage, I blamed myself, for drinking too much of the wrong kind of tea, for not getting enough rest, for not being "ready", etc. With my head, I knew all of that was wrong, but I wanted a REASON, so I could make it not happen again.

It hasn't happened again, but not because of anything I've done or not done, but that's a hard thing to let go of.

Awesome post! I have a one-week-old baby in my arms right now who was born naturally at a birth center after 40 weeks gestation, just like her big sister. There's somethiing to be said for letting things happen as they will.

P.S. about flu shots: I've gotten the flu once in my adult life, when I was about two months pregnant, and I felt absolutely miserable. I was under the impression that pregnant women weren't supposed to get vaccines, but learned it was not so only when it was too late.

Most years, I do make a point of getting a flu shot in the fall. Hell, if I'm this whiny with a head cold, I sure as hell don't need to catch the flu.

My husband was diag with Alzheimers at age 58 - I had to quit work 02/06 as he can't be alone now. When he still would disc. our situation, we always said "it could be worse".You're so right-it's just bad luck.He was a private pilot and accountant so no explanation helps us. We just know many are worse off - eg: ill children, etc.Thanks for listening- enjoy your blog.

Ozma, people also want to give themselves credit for luck and circumstance. "I'm successful because I work hard," they say...and because they grew up with attentive parents who read to them, and they went to good schools, etc. "Those people on welfare are just lazy"...and they lacked the advantages you take for granted, and face challenges you've never had to face.

I think that Ozma and Orange have come across the reasons for all of the theories and explainations.

A close family member had cancer and died of it. It was not a type of cancer that can be attributed to much other than bad luck. The family member (and to some extent the rest of us) made peace with the idea that it really was nothing but chaotic bad luck. However, many people around us really searched for the cause of the disease. I think that if people can pin down a reason that someone is suffering they can try to reassure themselves that it will not happen to them. It reality, there are some things that we can control and others that we cannot.

I have a question. In all probability, a very lame question -- based on your enthusiasm for the flu shot. But I'm one of those hippie-dippie people who doesn't like vaccines and such ;)

Let me start by saying that I know, for a fact, that the flu shot can't give you the flu. I have never, ever thought that. I'm a scientist (believe it or not) and I know that it's not possible. *But*, isn't it possible that while your body is processing the flu shot, your immune system is slightly comprimised and you're more likely to get sick from something (cold, flu, what have you....)? It does seem like everyone I know gets sick after the flu shot. But then again, I'm probably just noticing the "hits" and not the "misses".

I truly wish that my doctor didn't always feel the need to give me an answer. It always makes me lose respect for them when they assert something with total assurance. My husband and I have deduced that most patients must like this approach and that's why doctor's do it?

Once again, I find myself tempted to forward your posts to my mother. In addition to her tendency to follow me around with giant tumblers of ice water when she comes to visit, she also thinks getting a Ph.D. while parenting toddlers may cause all kinds physical ailments, from the flu to cancer.

Someone once told me that Berry Kix cereal put her into labor. I'm smart enough not to believe it but damn if I didn't buy and eat some when I was 40 weeks 2 days pregnant. And...you guessed it...I went into labor. Oh, but I also had a pitocin drip.

I went through a surgical technology class years ago. Our main instructor told us, "as a fact", that women who suffer from morning sickness only do so because somewhere in their mind they resent the pregnancy.

I have PCOS and my last pregnancy happened after we thought all hope was past - and I hurled just like I did with the first one (who came along a little lot easier but still was not resented).

great blog! I think it must be universal--I am a doctor mom, too, and believe me, at least in Georgia the crazies have all been out in full force, making for a very long week. February does that to people here. Its thunderstorming today, and folks just get a little nutty.

Then there are the people who think that stomach/intestinal illness is "the stomach flu," and that if they experience "the stomach flu" within a year of getting a flu shot, "the flu shot doesn't work" and then never get another flu shot.

Old MD Girl you said--Well, the bad luck can have a cause.... how about "genetic predisposition."

Definitely, genetic predisposition is a kind of bad luck. Your luck primarily begins in the DNA for sure.

Doesn't every event have a cause? Maybe there is some theory in quantum physics that events can occur without causes. But besides the very weird quantum anomaly, every event has a cause.

I don't know how much conflicting data on this there is but the NY Times Science or Health section had a story that said that only 3% of longevity is correlated to genetics. So if you get sick does it have to be one of these three things? (1) Genotype/phenotype (2) Environmental factors--like behavior, bacteria, virus, injury caused by some substance--this usually interacts with (1) but then there's aging which gets us all in the end.(3) A random incident of some kind--sort of a biological accident.

Or are there no accidents beyond (1) and (2)? I assume there are accidents with cancer since don't some cancers involve RNA replication errors? Complex systems like bodies malfunction, right? There's a cause but it isn't anything that can be controlled for and you can't point to a definite reason--like 'it's in your genes' or 'you ate too much fat'. I assume there is some explanation but maybe it is simply the complexity of biological processes and the fact they go wrong at times. There's a cause but it doesn't provide the kind of explanation we are usually satisfied by.

I thought maybe Dr. Mama was talking about (3).

Just curious. I don't think like a doctor so probably this makes no sense.

Hope your wretched day and week is now over and this week is less wretched Dr. Mama!

"I also think childbirth has been overmedicalized in general—I even think that the evidence supports the superiority of (supervised) homebirth in multiparous women."

This statement alone makes me LOVE LOVE LOVE YOU!!!!!Wow... are you for real? Someone pinch me!Mom to three little monsters...primary c/stwo hbacs with RM's (Canada) and one freak out on the medics who showed up late to the party without any infant resuss equipment or training in intubation (was never needed but STILL!)... the midwives had equipment x3 and intubation training every six months.... and people wonder why I don't trust the medical model anymore? You have my undivided attention now!!! Now if only I could find someone like you here!!!psst... the smallest one is "still" nursing too...